Robotmoose, as you can see the question of solo backpacking does generate quite a few comments and advice.

I agree with much of the advice given so far, especially about leaving an itinerary, gear description and instructions with someone who will notice if you do not come back on time. I presume after reading the discussion above that you understand that if you suffer any injury or incapacity while you are solo and off-trail, you'll either need to self-rescue or else carry a signaling device such as a PLB to summon help. Further, you can't predict when injury or incapacity might happen, so you'd better have a plan for it.

Now that you understand that, I expect what you had in mind when you posed the question was something more mundane than that. I backpack solo almost exclusively. It is a lot like hiking with someone else, but not quite. You listen more to your own mind when you are alone, surrounded by quiet. This can be a double-edged sword, especially if you aren't used to that much solitude.

You can always take something like an MP3 player to give you a way to distract your mind and give it something soothing to focus on, but I hope you'd reserve it for 'emergency' use only, because, as inane and fretful as your mind can be at times, I think the greatest gift of solo backpacking is that you get to hear yourself think. It isn't always pretty, but if you stick with it, it is very informative, even humbling.

It is especially humbling because there is never anyone to save you from your mistakes and no one else to blame when you do something incredibly stupid, as almost certainly you will. Lucky for you, there are no other witnesses, and those mistakes are rarely fatal.

Anyway, good luck. I think every experienced backpacker should give solo hiking a shot. Stay in familar territory to start with, with similar weather and terrain to that where you normally hike. A known trail is best for the first trip. I hope you try it and love it.